Concrete pile form



Feb. 28, 1961 J. J. KUPKA 2,972,872

' CONCRETE PILE' FORM Filed Jan. 17, 1958 s Sheets-Sheet 1 Feb. 28, 1961 J. J. KUPKA 2,972,872

CONCRETE PILE FORM FiledJan. 17, 1958 5 Sheets-Sheet .2

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INVENTOR.

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- CONCRETE PILE FORM Filed Jan. 17, 1958 1 3 Sheets-Sheet 5 13 Claims. (Cl. 61-,-53.52)

The invention herein disclosed relates to the construction of forms for concrete piles.

These forms have consisted usually of an outer shell which is left in the ground and an expansible core which is used to drive the shell and then contracted and removed to permit the shell being filled with the concrete which is to constitute the body of the pile.

The expansible cores have usually been made up of segments and the expansion eflected by spreading or separating these segments. As a result of such expansion, the shell is engaged at spaced points or areas defined by the extent of the separated segments. The driving of the form through the medium of these separate segments has definite disadvantages and it is an object of this invention to overcome and eliminate such disadvantages.

Accordingly, the present invention involves the utilization of a tubular driving element insertable within the shell, split longitudinally to render it expansible and .contractable, this split tubular member engaging a driving head at the lower end and engageable by the driving harnmer at the upper end so as to carry the full driving load independently of any spreading or contracting mechanism and the mechanism for effecting expansion and contraction of the split tubular driving member being located Within that member and operable one way or the other through lowering and lifting connections made with the hammer. a

To eliect practically continuous driving connectionrbetween the split tubular member and shell, the tube may be wrapped with a layer of elastic rubber-like material which will provide practically continuous gripping connection between the two and serve also as a closure over the split in the tube.

Other desirable objects attained by the invention and,

further novel features of construction, combination and relation of parts are set forth or will appear in the course of the following specification. Y

The drawings accompanying and. forming part of the specification illustrate a present, practical embodiment of the invention. Structure, however, may be modified and changed within the true intent and scope of the invention as hereinafter defined and claimed.

Fig. l in the drawings is a broken longitudinal sectional view of a concrete pile form incorporating the invention, showing theexpanding bar in its upper position with the split drive tube in contracted relation, free or releasable from the shell. a

Fig. 2 is an enlarged broken sectional view of the upper end portion of the form showing the anvil of the hammer lowered in driving engagement with the upper end of the tube after having forced the expanding bar downwardtoexpand the split tube into gripping engagement with the shell.

Figs. 3 and 4 are enlarged cross-sectional views on substantially the plane of line 34 of Fig. 1, showing one of the toggles in contracted and expanding positions, respectively.

Figs. 5 and 6 are broken front elevation and part sectional views of the shell and collapsible core members of the form. 7

Fig. 7 is a horizontal sectional view of the upper end of the core frame on substantially the plane of line 77 I end of the core trame'on substantially the plane of line 88 of Fig. 7. I I

The shell, whichin the end constitutes the actual form for the concrete, is shown at 10 as a helically corrugated sheetmetal structure having a hollow driving point 11 at the lower end and open at the upper end. Since, according'to the present invention, this is interiorly reinforced substantially throughout, it may be a relatively light, inexpensive,tubular member.

The expansible and contractable core or mandrel comprises a cylindrical tube 12 of light but durable spring steel capable of carrying the driving load and split longitudinally as indicated at 13 to render it expansible under internal pressure and self-contracting on release of expanding pressure.v To make engagement between the inner expansible member and outer surrounding shell as nearly complete as possible, the split tube is shown as covered by helical winding 14, Fig. 6, of rubber or composition tape which, as indicated in Fig. 2, will squeeze into and around the convolutions in the helically corrugated shell under expanding pressure of the split tube.

While the full length of the shell is subjected to the driving effort, the main force is applied to the conical driving head or point 15, Fig. 1, which fits within the hollow driving point 11 of the shell and which has an annular shoulder 16 engaged by the lower end of the tube. The upper end of the tube is shown left exposed to be engaged by and take the full impact of the anvil 17, Fig. l, of the hammer. I

The hammer is not shown since it may be of any usual or special design. It is, however, in the present illustration of special construction in that the anvil 17 is made to cooperate with'the core for hoisting, expanding and contracting the same. a

Fig. 1 shows this anvil as having a center conical socket 18 in the bottom of the same, opening through a circular passage 19 into an enlarged chamber 20 and thus providing an annular shoulder 21 for the companion core supporting hooks 22. Also, as shown in Fig. l, the anvil has a beveled contour 23 about the center socket for guiding it into the open upper end of the core tube and a surrounding annular shoulder 24 for seating it in driving engagement on the upper end of the tube.

The suspension hooks 22 are shown pivotally mounted at 25 on the upper end of a pull bar or link 26, longitudinally shiftable in the core and as having their lower ends below the pivot center connected by a spring 27 for spreading the hooks into engagement over the supporting shoulder 21.

The book carrying bar 26 is shown as shiftably guided in a frame made up of oppositely disposed channels 28, 29, bolted at 30, Fig. 1, to opposite sides of a projection 31 rising from the driving point 15.

A top head 32, Fig. 7, is shown secured between the upper ends of the channels by having bosses 33 extended through and welded to the channels and this head is indicated as having a central rectangular passage 34 for the upper end of bar 26, hooks 22 and pivot pin 25.

This top head 32 serves as an abutment limiting upward movement of the pull bar 26, the latter having shoulders as shown at 35, Fig. 2, for engagement wit the underside of the head.

Expansion of the split tube is effected through the medium of cams 36 on bar 26 engageable with rollers 37 journalled at 38' on cross-slides 39 mounted for trans- 3 verse sliding movement in guides 40 on the channel 28 and connected at the inner ends by pivots 41 with companion toggle levers 42 carrying rollers 43 at their free ends operating through guides 44 into engagement with the inner wall of the tube at opposite sides of the split.

Fig. 3 shows the position of parts with the bar 26 in raised position as in Fig. 1 and the transverse slide retracted, with toggle levers 42 in the broken relation permitting contraction of the split tube.

Fig. 4 shows the position of parts with the cam bar 26 lowered as in Fig. 2, with cams 36 forcing rollers 37 radially outward causing slides 39 to spread or tend to straighten the toggle levers, thus to expand the split tube.

The cams 36 are shown in Figs. 1 and 2 as terminating in lands 45, arranged when the bar is fully lowered, to hold the slides in the toggle spreading relation, Figs. 2 and 4.

The outward thrust of the toggle spreading slides is shown in Figs. 2 and 4 as taken up by engagement of the rounded outer ends 46 of the slides with the inner surface of the tube substantially diametrically opposite the split. This, as will be evident in Figs. 3 and 4, provides a three point spreading engagement with the tube substantially equalizing spreading forces and maintaining the tube substantially cylindrical, in full, firm gripping engagement with the surrounding shield.

Back pressure of the cams is taken up in the present disclosure by engagement of the back of the cam bar 26 with rollers 47 journalled in brackets 48 bolted at 49 on the inside of the channel 29.

In this invention, the tube expanding mechanism is separate from the driving organization and does not have to carry the driving loads.

To further accomplish this separation of expander and driver mechanisms, the expander may be shock-insulated from the other parts by placement of rubber or other cushioning pads 56, Fig. 1, between channels 28, 29 and the drive head projection 31 and rubber or similar bush ings 51 about the securing bolts 30.

The spreader or expander is thus given a floating support on the drive head enabling it to compensate and somewhat adjust itself to the split tube.

The expansible split tube to a similar effect has a selfadjusting floating mounting on the drive head 15 enabling it to seat fully thereon under the blows of the hammer.

The expansible core may be connected with the hammer by simply lowering the hammer so as to cause the anvil 17, Fig. 1, to engage the hooks 22 which will thereupon be contracted by the bevelled socket 18 until the anvil lowers sufiiciently for them to pass up through passage 19 into the upper chamber 30, whereupon spring 27 will snap the hooks into engagement over the annular suspension shoulder 21, the relation shown in Fig. 2.

Thus coupled to the hammer, the hoist gear of the hammer may be used to transport the core and to lower it into position in the shell. Thus suspended from the hammer anvil, the cam bar 26 will be at the top of its stroke with stop shoulders 35 thereon in abutment with the upper head 32 of the expander frame.

The core can thus be lowered into the shell with the split spring tube automatically in fully contracted relation. When the core is fully lowered in the shell with the driving head 15 fully seated in the hollow driving nose 11 of the shell, the anvil by engagement of the top of the chamber 29 with the upper ends of the hooks, will force the cam bar downward into the Fig. 2 position to effect expansion of the split tube into gripping engagement with the shell. The lands 45 at the upper ends of the cams will then hold the tube expanded so that the hammer can be put into action just as soon as the core is fully lowered into the shell.

In reverse fashion, it is only necessary to liftthe hammer to eifect contraction of the split tube and removal of the contracted core from the shell, the upward lift of the hammer through the medium of the hooks seated in the anvil first raising the cam bar to release the spreader slides as in Figs. 1 and 3, and further movement extracting the coupled core from the shell.

To release the core from the hammer, the spring expanded hooks 22 may be contracted by a pair of tongs or equivalent hook engaging tool inserted between the anvil and upper end of the split tube when these parts are separated for the purpose and the core is supported so as to relieve the hooks of load.

For driving long piles, extra lengths of shell may be added to the bottom shell by welding or otherwise attaching adjoining ends of the shells.

Fig. 2 illustrates how this may be accomplished by using an expansible core in each added length having an anvil 17a at the bottom of the same similar to the hammer anvil 17 for coupling with the hooks 22 of the lower core and for seated driving engagement on the upper end of the split tube 12 of the lower core.

What is claimed is:

1. Form for a concrete pile comprising the combination of a shell adapted to be driven and left in the ground as a form for the concrete and a core expansible to effect driving engagement with the shell and contractible to effect release and permit removal of the core from the driven shell, said core having a driving shoe at the lower end provided with an upwardly faced annular driving shoulder, a longitudinally split spring driving tube within said shell centered in driving engagement at its lower end on said annular shoulder, said split tube being of spring material and tensioned to a normally substantially closed contracted condition free of the surrounding shell but expansible under internal pressure, a cushion of resilient gripping material on said split tube positioned to be forced by expansion of the tube into gripping driving engagement with the surrounding shell, an upright frame mounted on said driving shoe within said split tube, expansible and contractible tube expanders on said frame in thrust applying spreading engagement with the tube at opposite sides of the split therein, a hammer element having a downwardly faced annular shoulder in driving engagement with the upper end of the split tube and means operable by said hammer element for imparting tube expansive movement to said tube expanders on downward movement of said hammer element and for effecting contraction of said expanders and lifting of the core upon upward movement of said hammer element.

2. The invention according to claim 1 in which said means includes a cam bar guided for limited lifting and lowering movement in said frame having cams and rollers on said expanders engageable by said cams for spreading said expanders on downward movement of the bar.

3. The invention according to claim 1 in which said means includes a cam bar guided for limited lifting and lowering movement in said frame and cross slides carrying rollers operable by said cam bar, said expanders including toggles operable by said cross slides.

4. The invention according to claim 1 in which said tube expanders include horizontally shiftable thrust members engageable with the tube substantially opposite the split therein and toggle members connected with said thrust members and engageable with the tube at opposite sides of the split therein.

5. The invention according to claim 1 in which said tube expanders comprise thrust members engaged with the tube substantially opposite the split therein and spreader elements engageable with the tube at opposite sides of the split therein.

6. The invention according to claim 1 in which said means include a bar having limited vertical shifting movement in said frame, suspension books on the upper end of said bar, said hammer element having a supporting shoulder engageable by said suspension hooks.

7. A form for a concrete pile comprising the combination of a shell adapted to be driven into and left in the ground as a form for the concrete and a core expansible into driving engagement with the shell and contractible to effect release and permit removal of the core from the driven shell, said core comprising a onepiece drive tube of inherently springy material located within and of less diameter than said shell, said drive tube being split longitudinally and tensioned to a contracted state free of the surrounding shell but expansible by internal pressure into gripping, driving engagement with the shell, a shell driving shoe in driven engagement with the lower end of said split drive tube, a drive member in driving engagement-With the upper end of said split drive tube, a center support extending from said drive shoe up through said drive tube, clear of said drive tube and free of said drive member at the upper end of the tube so as to be unaifected by blows delivered by the driving member on the tube, tube expanding means mounted on said center support within said split drive tube and means for effecting operation of said tube expanding means to expand said split tube into driving engagement with the surrounding shell or to efiiect contraction of said split tube and release of the core from the shell.

8. The invention according to claim 7 with a cushion of shell gripping material about said tube and comprising a strip of resilient material wrapped helically about said tube and covering the split in said tube.

9. The invention according to claim 7 with a shock absorbing yielding connection between said driving shoe and the lower end of said center support.

10. The invention according to claim 7 in which said frame comprises spaced opposed channels connected at their lower ends with said driving head, head structure connecting the upper ends of said channels, a cam bar guided for vertical sliding movement between said channels and operating up through said upper head structure and said tube expanders comprising slides transversely operable in the frame into and out of thrust applying engagement with the tube substantially opposite the split in the tube and toggle levers connected with said slides and transversely operable into thrust applying engagement with the interior of the tube at opposite sides of the split in the tube.

11. Form for a concrete pile comprising the combination of a shell adapted to be driven into and left in the ground as a form for the concrete and a core expansible into driving engagement with the shell and contractible to eifect release and permit removal of the core from the driven shell, said core including a longitudinally split drive tube within and of smaller diameter than said shell, said split drive tube being of spring material spring tensioned to a normally substantially closed condition out of driving relation with the shell but expansible under internal pressure into driving relation with the surrounding shell, a driving member in driving engagement with the upper end of said split drive tube and a shell driving shoe in driven engagement with the lower end of said split drive tube, tube expanding means within said split drive tube and means for controlling said tube expanding means to eliect driving engagement of said split drive tube with the surrounding shell or the release of said tube from driving engagement with the shell.

12. The invention according to claim 7 with a sleeve of rubber-like material surrounding said split tube, covering the split in said tube and expandable by said split tube into gripping engagement with the shell.

13. The invention according to claim 11 in which said References Cited in the file of this patent UNITED STATES PATENTS 1,403,766 Gillies Jan. 17, 1922 1,773,205 Smith Aug. 19, 1930 1,865,653 Upson July 5, 1932 2,437,043 Riemenschneider Mar. 2, 1948 2,840,993 Caudill July 1, 1958 2,871,666 Pickman Feb. 3, 1959 

